Metal Stock Research Articles

Comparative evaluation and co-relation in variation of curve of Spee and curve of Wilson in Class II div. 1, Class II div. 2, and Class III as against Class I malocclusion in central India population- an in vitro study

Introduction Getting acceptable cosmetic results in the soft tissues of the face serves as the foundation for orthodontic treatment planning. Also, in order to achieve healthy static and dynamic occlusal interactions, the teeth must be positioned within the basal bone at the correct position, angle, and inclination. To avoid periodontal issues, provide stability, and achieve a functional occlusion, it is essential to ascertain the individual’s dental arch form before starting of treatment and thus to utilise the mechanics that follow throughout the treatment. Objectives To evaluate and compare variation in Curve of Spee and Curve of Wilson in Class II Div.-1, Class II-Div-2 and Class-III as against Class I malocclusion in central India population. Methodology Irreversible hydrocolloid impression will be taken with perforated metal stock trays and stone cast will be poured. This will be scanned using CAD CAM machine and curve of Spee and Wilson will be measured using reverse engineering. Expected Result It will assist us in treatment planning for preventing periodontal issues, assuring stability, and achieving functional occlusion by evaluating and comparing the Spee and Wilson curves in Class II Divison-1, Class II Divison-2, and Class-III malocclusion with Class-I malocclusion. Conclusion Every single patient receiving orthodontic treatment has the COS, which is crucial to achieving a stable occlusion. Almost every patient who receives orthodontic treatment eventually experiences the Spee Curve. Since there aren’t many studies examining the relationship between the Curves of Spee and Wilson, their impact on dentoskeletal morphology, and their role in occlusal stability.

Security evaluation of China's indium industrial chain: Perspective on substance flow throughout the whole life cycle

As the world's largest supplier of primary indium, China's indium industrial chain structure and demand change affect global supply. It is necessary to evaluate the security of China's indium industrial chain and determine the reasons that affect security. The past substance flow analysis (SFA) of indium and mineral industrial chain security evaluation has problems such as a lack of timeliness, a single dimension mainly focusing on the upstream, and simple evaluation methods. In this paper, based on the SFA, an integrated evaluation system for the whole life cycle is constructed from 2000 to 2022 according to mineral industrial chain security characteristics. The results show that since introducing liquid crystal in 2003, China's indium industrial chain security level has been low despite a slight increase. Although China has gradually broken through the production technology of high-purity indium and indium tin oxide (ITO) targets, the large consumption and export of refined indium has reduced China's indium metal stock to 2214 t, while the resource reserves advantage is also diminishing. Mass consumption has also led China to import more ores, while China still imports high-end products from other countries with high import source concentrations. The pollutants emitted by the large production and the declining environmental governance level pose a significant environmental threat. Finally, suggestions for strengthening international cooperation, increasing technological research, establishing a reserve system, risk monitoring mechanisms, and strict emission standards can improve China's indium industrial chain security.

Comparative evaluation and co-relation in variation of curve of Spee and curve of Wilson in Class II div. 1, Class II div. 2, and Class III as against Class I malocclusion in central India population- an in vitro study.

Getting acceptable cosmetic results in the soft tissues of the face serves as the foundation for orthodontic treatment planning. Also, in order to achieve healthy static and dynamic occlusal interactions, the teeth must be positioned within the basal bone at the correct position, angle, and inclination. To avoid periodontal issues, provide stability, and achieve a functional occlusion, it is essential to ascertain the individual's dental arch form before starting of treatment and thus to utilise the mechanics that follow throughout the treatment. To evaluate and compare variation in Curve of Spee and Curve of Wilson in Class II Div.-1, Class II-Div-2 and Class-III as against Class I malocclusion in central India population. Irreversible hydrocolloid impression will be taken with perforated metal stock trays and stone cast will be poured. This will be scanned using CAD CAM machine and curve of Spee and Wilson will be measured using reverse engineering. It will assist us in treatment planning for preventing periodontal issues, assuring stability, and achieving functional occlusion by evaluating and comparing the Spee and Wilson curves in Class II Divison-1, Class II Divison-2, and Class-III malocclusion with Class-I malocclusion. Every single patient receiving orthodontic treatment has the COS, which is crucial to achieving a stable occlusion. Almost every patient who receives orthodontic treatment eventually experiences the Spee Curve. Since there aren't many studies examining the relationship between the Curves of Spee and Wilson, their impact on dentoskeletal morphology, and their role in occlusal stability.

Evaluation of Implant Impression Accuracy Using Different Trays and Techniques with a 3D Superimposition Method.

To evaluate the dimensional accuracy of implant impressions obtained using five different tray types and two techniques. A partially dentate maxillary Kennedy Class II model was created as a reference model through 3D printing. Then, implant analogs 4.3 mm in diameter were placed at the first premolar, first molar, and second molar sites. Five types of trays were used to create impressions: (1) metal stock trays, (2) plastic stock trays, (3) custom trays fabricated using liquid crystal display (LCD), (4) custom trays fabricated using fused deposition modeling (FDM), and (5) custom trays fabricated using urethane dimethacrylate (UDMA) resin. Open and closed tray techniques were also compared. In total, 150 impressions were obtained. The reference model and impressions were scanned using a laboratory scanner. Additionally, the positional and angular deviations of implants with different tray types and techniques were evaluated using the superimposition method. There was no statistically significant difference (P > .05) between the impression accuracy with the different tray types and impression techniques. The angular deviations with plastic and UDMA trays were greater than those with metal, FDM, and LCD trays. Angular deviation at the second molar was greater when using closed plastic trays compared to open plastic trays. The highest and lowest positional deviations were observed at the first molar implant with an open plastic tray impression (mean ± SD of 62.46 ± 28.54 mm) and a closed LCD tray impression (36.59 ± 29.93 mm). The greatest angular deviation was observed with an open FDM tray impression at the first premolar implant (0.067 ± 0.024 degree), and the lowest angular deviation was observed with a closed metal stock tray impression at the second molar implant (0.039 ± 0.025 degree). Statistical differences were detected using the Mann-Whitney U test for paired groups and the Kruskal-Wallis test for groups with more than three comparisons (P > .05). Plastic and metal stock trays or conventional and 3D-printed custom trays can be used to obtain implant impressions for maxillary partially edentulous arches with similar dimensional accuracy. The five tray types and two techniques may be safely used to obtain impressions of partially edentulous maxillary arches with three implants.

ANTI-CORROSION COATING BASED ON PRODUCTION AND CONSUMPTION WASTE

The process of corrosive decay of metal products leads to serious consequences both for the products themselves and for the quality of the environment, therefore protection against corrosion is carried out by isolating structures from an aggressive environment using various protective coatings. One of the promising directions in the sphere of corrosion protection is the production of such coatings based on waste with anti-corrosion potential (galvanic sludge, used motor oil), which is thesubject of this article. On the basis of the analysis of chemical composition and physicochemi-cal characteristics of the considered wastes the possibility of their use for obtaining effective anti-corrosion coating is proved. The realization of the proposed technology makes it possible to solve a number of topical issues of important social and economic importance, namely the problem of the accumulation of hazardous waste and the preservation of the general metal stock.

Study of the Influence of Ultraviolet Radiation as an Aging Intensificant on the Rubber Products Operated in the Agricultural Complex

The factors reducing the safety and operational potential of the metal stock of agricultural machinery are considered. It has been established that the condition of rubber products has a significant influence on it. It is assumed that exposure to ultraviolet radiation is the most representative critical factor for the physical and mechanical properties of rubber products. The methodology for experimental research has been developed, as well as a software interpretation system based on the Matlab libraries.

DETERMINATION OF TOXIC HEAVY METALS IN CHOLIC ACID USING QUADRUPOLE INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

Objective: The information on the presence of toxic heavy metals in pharmaceutical starting materials and finished product is very crucial from the viewpoint of human life and its hazardous impact on the worldwide environment. The present work deals with the detailed quantification of the toxic heavy metals, namely, V, Co, Ni, Cd, Hg, Pb, and As, present in colic acid using quadrupole inductively coupled plasma mass spectrometry (Q-ICPMS) with prior microwave-assisted digestion. Moreover, the preliminary characterization of commercially available cholic acid by FT-IR, NMR (1H and 13C), SEM-EDAX has also been carried out. Methods: Cholic acid of synthesis grade, Nitric acid (65%) AR. grade, ethylene diamine tetra acetic acid sodium salt AR grade, and certified reference metal stock standard solutions (1000 mg/L) of multiple elements prepared in 2–3% HNO3 of analytical grade were purchased from Merck (Darmstadt, Germany). All the samples were treated with nitric acid and microwave-assisted digestion. For the accurate determination of the elemental amount, various digested solutions and post-digestion diluents were tested. The linearity, accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ) of the analytical technique were evaluated in accordance with the United States Pharmacopoeia 233 standard. Results and Discussion: The Q-ICPMS-based analytical method was validated for specificity, LOD, LOQ, linearity, accuracy, precision, and uncertainty. The estimated detection limits of the toxic heavy metals in cholic acid were in the range 2–180 μg/L. The quantification limits were in the range of 1.5–60 μg/L. Mean recoveries±standard deviations at different spiking levels were in the range 75.3±2.1–104.9±8.5%. The coefficients of variation were in the range of 0.5–8.1%. Conclusion: The precision of the analytical method, in terms of relative standard deviation, was below 1.95%. The uncertainty in the quantification of all the validated elements was found to be ≤1.70% for Sample 1.

DETERMINATION OF TOXIC HEAVY METALS IN CHOLIC ACID USING QUADRUPOLE INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

Objective: The information on the presence of toxic heavy metals in pharmaceutical starting materials and finished product is very crucial from the viewpoint of human life and its hazardous impact on the worldwide environment. The present work deals with the detailed quantification of the toxic heavy metals, namely, V, Co, Ni, Cd, Hg, Pb, and As, present in colic acid using quadrupole inductively coupled plasma mass spectrometry (Q-ICPMS) with prior microwave-assisted digestion. Moreover, the preliminary characterization of commercially available cholic acid by FT-IR, NMR (1H and 13C), SEM-EDAX has also been carried out. Methods: Cholic acid of synthesis grade, Nitric acid (65%) AR. grade, ethylene diamine tetra acetic acid sodium salt AR grade, and certified reference metal stock standard solutions (1000 mg/L) of multiple elements prepared in 2–3% HNO3 of analytical grade were purchased from Merck (Darmstadt, Germany). All the samples were treated with nitric acid and microwave-assisted digestion. For the accurate determination of the elemental amount, various digested solutions and post-digestion diluents were tested. The linearity, accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ) of the analytical technique were evaluated in accordance with the United States Pharmacopoeia 233 standard. Results and Discussion: The Q-ICPMS-based analytical method was validated for specificity, LOD, LOQ, linearity, accuracy, precision, and uncertainty. The estimated detection limits of the toxic heavy metals in cholic acid were in the range 2–180 μg/L. The quantification limits were in the range of 1.5–60 μg/L. Mean recoveries±standard deviations at different spiking levels were in the range 75.3±2.1–104.9±8.5%. The coefficients of variation were in the range of 0.5–8.1%. Conclusion: The precision of the analytical method, in terms of relative standard deviation, was below 1.95%. The uncertainty in the quantification of all the validated elements was found to be ≤1.70% for Sample 1.

STOCKS OF POTENTIALLY TOXIC ELEMENTS IN THE GROUND COVER OF NORTHERN TAIGA PINE FORESTS UNDER AEROTECHNOGENIC POLLUTION

The paper presents the results of studying the distribution of stocks of potentially toxic elements (Ni, Cu) in subcrown spaces and “windows” of stands in medium-aged pine forests in the background area of the Kola Peninsula and that under environmental pollution by atmospheric emissions of the Severonickel Combine (Monchegorsk, Murmansk Region). On the basis of previously obtained data on the stocks of aboveground biomass of the components of the ground cover, mortmass of plant debris and forest litter and data of chemical analysis by means of atomic absorption spectrometry of leaves of dominant shrub species, aboveground parts of the moss Pleurozium schreberi (Brid.) Mitt, and lichen Cladonia stellaris (Opiz) Pouzar et Vězda, as well as plant waste and organogenic horizon (forest litter) of Al-Fe-humus podzols, Ni and Cu stocks in different components of forest ecosystems were calculated. It was found that the sharp decrease in atmospheric emissions by the Severonickel Combine over the last 20 years has not affected the level of habitat contamination, and the stock of heavy metals in the upper organogenic horizon of Al-Fe-humus podzols remains very high, especially in the impact zone, which does not even allow to start the process of restoration of the ground cover in this area. The stock of heavy metals in the plant waste consistently increases with the increase in the level of forest litter contamination when approaching the source of pollution, but the scale of this increase is significantly smaller in the mortmass compared to the litter. The pattern of distribution of heavy metal stocks in components of ground cover, plant waste and forest litter over the phytocenosis area is fundamentally different in background conditions and under aerotechnogenic pollution, which is due to differences in the accumulation of organic matter in different types of microsites. The ratio of Ni : Cu concentrations and stocks also differs in the soil-vegetation cover in pine forests of the background area and under the influence of aerotechnogenic pollution.

SPENDING A WINDFALL

AbstractWe study the effect of the discovery of precious metals in America from 1500 to 1810 on international trade. Around 1500, there was a simultaneous discovery of precious metals and new trading routes. We construct a counterfactual of new routes but no precious metals. The discovery of precious metals increased the stock of precious metals more than 10‐fold. We show that Euro‐Asian trade at its peak increased up to 20 times compared with the counterfactual. Our simulations match the observed price dynamics. We find that precious metals were at least as important as the new routes.

Complementarity of road salt and heavy metal pollutant removal through invasive Typha and Phragmites harvest in urban wetland detention basins

Plant-based bioremediation has been proposed as a strategy to mitigate the growing risks associated with freshwater salinization, but large-scale experimental field tests of how harvesting plants can reduce deicing salts and heavy metals common in roadside environments are lacking. We implemented a three-year, large-scale field experiment (across 180 ha) in ten urban wetland detention basins in the Chicago region (Illinois, USA) to investigate the potential of plant biomass harvest to remove salts and heavy metals from roadside environments. Harvesting both Typha and Phragmites, ubiquitous plants that co-occur in wetlands around the globe, has the potential to remove both salts (Na, Cl, Ca, Mg) and heavy metals (Zn, Cu, Fe, Mn), as we observed complementarity in the pollutants concentrated in the aboveground tissues of these two species. We observed greater salt stocks in Typha biomass while heavy metals (especially Zn) were more abundant in Phragmites. Salts associated with deicing salts (Na, Cl) were particularly concentrated in live green Typha tissue, while metals tended to be more abundant (>50% of total stocks) in senescent litter, suggesting that plant phenology is important to consider when mitigating target pollutants via harvesting. Although repeated harvests reduced aboveground biomass and associated salt and metal stocks relative to unmanipulated controls, rotational harvest of common macrophytes growing in road-adjacent wetlands could maximize the reduction of roadside pollutants through harvesting. However, our data suggest that harvesting invasive macrophytes from urban roadside detention basins is not a silver bullet to remedy freshwater salinization, as it mitigates only a small fraction of added road salt loads.

On the similarities between precious metals, precious metal stocks and equities – International evidence for gold and silver

The study attempts to assess if the precious metal stocks behave more like their metal or stock counterparts. We use both Maximal Overlap Discrete Wavelet Transform and Continuous Wavelet Transform to test the time and frequency-varying association of precious metal stocks with the precious metals and broader equity indices. The empirical shreds of evidence are suggestive that precious metal stocks behave more like precious metals than common stocks. The results bear important policy implications for the multi-horizon investors wishing to expose themselves to precious metal stocks, precious metals and common stocks.

Comparative evaluation and co-relation in variation of curve of Spee and curve of Wilson in Class II div. 1, Class II div. 2, and Class III as against Class I malocclusion in central India population- an in vitro study

Introduction- Getting acceptable cosmetic results in the soft tissues of the face serves as the foundation for orthodontic treatment planning. Also, in order to achieve healthy static and dynamic occlusal interactions, the teeth must be positioned within the basal bone at the correct position, angle, and inclination. To avoid periodontal issues, provide stability, and achieve a functional occlusion, it is essential to ascertain the individual's dental arch form before starting of treatment and thus to utilise the mechanics that follow throughout the treatment. Objectives- To evaluate and compare variation in Curve of Spee and Curve of Wilson in Class II Div.-1, Class II-Div-2 and Class-III as against Class I malocclusion in central India population. Methodology- Irreversible hydrocolloid impression will be taken with perforated metal stock trays and stone cast will be poured. This will be scanned using CAD CAM machine and curve of Spee and Wilson will be measured using reverse engineering. Expected Result- It will assist us in treatment planning for preventing periodontal issues, assuring stability, and achieving functional occlusion by evaluating and comparing the Spee and Wilson curves in Class II Divison-1, Class II Divison-2, and Class-III malocclusion with Class-I malocclusion. Conclusion- Every single patient receiving orthodontic treatment has the COS, which is crucial to achieving a stable occlusion. Almost every patient who receives orthodontic treatment eventually experiences the Spee Curve. Since there aren't many studies examining the relationship between the Curves of Spee and Wilson, their impact on dentoskeletal morphology, and their role in occlusal stability.

Spatial Layout Assessment of Urban Mining Pilot Bases in China Based on Multi-Source Data Collaboration

Rapid urbanization in China has led to an exponential increase in the stocks of metals used in cities. Exploring their amount and growth patterns is an important way to forecast future metal demand and identify the potential for urban mining. Here, we use a combination of bottom-up and GIS tools to estimate the amount of in-use stocks and scrap metal of steel, copper, and aluminum in 366 regions of mainland China from 2010 to 2020. We then downscaled the 2020 metal scrap volume based on a multi-source dataset of socioeconomic factors. Finally, the accessibility of the urban mining pilot base (UMPB) was calculated using the two-step floating catchment area method (2SFCA), and the spatial layout assessment analysis of the UMPB was conducted under the supply–demand balance perspective. The results showed that the total in-use stocks of steel, copper, and aluminum increased from an initial 3186 million tons to 5216 million tons, with a corresponding trend of continued growth in the amount of metal scrap. The high value of scrap metal in 2020 is concentrated in the Beijing–Tianjin–Hebei urban agglomeration, the Yangtze River Delta region, and the Chengdu–Chongqing metropolitan area. The accessibility results show that the road network distance-based accessibility covered a smaller area than the Euclidean distance-based accessibility, but when the UMPB service radius was set to 300 km, the road network distance-based accessibility could also cover most of the eastern part of China. The spatial evaluation results of UMPB show that for service radii of 200 km and 300 km, low-supply and high-demand areas account for 6.32 percent and 5.89 percent, respectively.

The impact of oil shocks from different sources on China's clean energy metal stocks: An analysis of spillover effects based on a time-varying perspective

In order to examine the impact of oil shocks from different sources on clean energy metals in China. This paper first obtains different sources of oil shocks, namely, oil supply shocks, oil demand shocks and oil risk shocks, and then uses the TVP-VAR model to investigate the time-varying effects and point-in-time impacts of different sources of oil shocks on Chinese clean energy metal stocks. The results show that, firstly, oil shocks from different sources have time-varying and heterogeneous effects on clean energy metal stocks. Compared to other oil shocks, the impact of oil demand shocks is the largest. Due to the different status and nature of different clean energy metals, the impact of different sources of oil shocks is different. At different time points of major events, the impact of different sources of oil shocks is different. Therefore, there is a need to focus on the impact of different events.

Net zero climate remediations and potential terminal depletion of global critical metal resources: A synoptic geological perspective

• Climate change accords led to widespread acceptance of Net Zero by 2060 targets. • Critical metals depletion making low carbon technology production impossible. • Climate change in geological perspective is slow incremental not catastrophic. • A reset in Net Zero ambitions should be made for the future. Over the past two decades, concerns about anthropogenic CO 2 emissions have led to computer-based climate models of the consequences, first on global warming and then on more general climate change. The more extremes of these models have been used to engender concerns about climate events that could be catastrophic for global populations even though natural climate change has always been incremental with only periodic large volcanic eruptions producing short-term catastrophic changes due to massive additions of aerosols to the atmosphere. Climate change accords have led to widespread acceptance of Net Zero by 2060 targets. However, indicative modelling of the nexus between clean energy and the critical metals required for low carbon solar and wind technologies and electric vehicles and their chargers indicates that many metals, particularly Co, Ni, Cu, Se, Ag, Cd, In, Te, and Pt, may be severely to terminally depleted by 2060, making further low carbon technology production impossible. Mineral exploration and currently unmined deposits with high risk factors are only likely to be able to replace these non-renewable metals at lower grades in more inaccessible or deeper mines, leading to even further increases in conventional energy for mining and metallurgy and consequent cost of the low carbon technology revolution. There is no current indication that recycling can replace the critical metal stocks. The heterogeneous global distribution of both mineral deposits containing the critical metals and production points could become a geopolitical issue if global security declines. These factors combined with the slow incremental, rather than catastrophic, changes related to climate change, suggest that a reset in Net Zero ambitions should be made to consider a more multicomponent plan for the future that involves a balanced portfolio of least polluting energy sources that do not cause serious depletion of affordable metal resources for the future. Graphical Abstract. .

Prospects of metal recovery from wastewater and brine

Modern technology relies on an undisrupted supply of metals, yet many metals have limited geological deposits. Recovering metals from wastewater and brine could augment metal stocks, but there is little guidance on which metals to prioritize for recovery or on the techno-economic viability of extraction processes. Here we critically assess the potential for recovering metals from wastewater and brine. We first look at which metals are critical for recovery on the basis of their supply risks and the impacts of those supply restrictions. We then assess the feasibility of recovering these metals from various water sources by estimating the required operational costs to match market prices. Next we discuss the limitations of established separation technologies that may inhibit the practicality and scalability of metal recovery from water. We conclude by highlighting materials and processes that could serve as more sustainable alternatives to metal recovery with further research and development. Recovering metals from wastewater and brine could augment metal stocks that are fundamental to modern technology. This Perspective assesses the potential of, and provides guidance for, recovering metals from wastewater and brine.

H3O-LGBM: hybrid Harris hawk optimization based light gradient boosting machine model for real-time trading.

The gross domestic product (GDP) of a country is mainly dependent on its trade and external sector which improves the country's income. According to FY2021-2022, India's nominal GDP is estimated to be 3.12 trillion US dollars. Overall exports and imports have a year-over-year increase of 49.6% and 68% respectively. Machine learning techniques have the potential to improve India's Current gross value by up to 15% by the year 2035. The integration of data, Technology, and talent helps to create intelligent models that enhance artificial intelligence growth. This paper presents an optimized light gradient boosting machine (Light GBM) model using the hybrid Harris hawk optimization (H3O) algorithm for trade forecasting. The overfitting problem in the conventional Harris Hawk Optimization is overcome using the exclusive feature bundling (EFB) and the gradient-based one-side sampling (GOSS) methodologies. The H3O optimization algorithm offers fast convergence by optimizing different lightGBM parameters such as a number of training iterations, maximum depth, minimal data in the leaf, etc. To improve the performance, one step further, the residual errors of the optimized lightGBM model are corrected using the Markov Chain model. The main aim of the optimized lightGBM model is to extract the crucial input values of certain variables such as imports and exports of goods and services, service trade, and merchandise trade and predict the price movement decision. The proposed model identifies the interrelationship with the external market and future market growth along with analyzing the variation in market conditions. The prediction decision is mainly to hold, but, or sell the stocks. When evaluated using the precious metal price forecast and stock market datasets, the proposed methodology shows that the hybrid approach can enhance the prediction performance. The results show that the input parameters were efficient in predicting the economic growth regarding the Intermarket trading system (ITS) and services with higher accuracy.

Spatial and in-product density characterization of in-use copper stocks in Japan for stock recyclability assessment

In-use metal stocks comprise various products, and their recyclability is determined by several factors. Hence, a comprehensive characterization of in-use stocks is required for stock recyclability assessment. We characterized in-use copper stocks in Japan by introducing two indicators to represent stock attributes relevant to recyclability: spatial density (SD) and in-product density (PD). SD is based on the spatial distribution of in-use stock, which is estimated by material flow analysis. PD is quantified based on the disassembly tree and level concepts and input-output analysis framework. Infrastructure-related products exhibited a relatively weak correlation with population and low SD, suggesting relatively large efforts required for collection. In contrast, information and communication electronics exhibited higher SD but lower PD, suggesting relatively large efforts required for preprocessing and recovery stages. Furthermore, integrated density characterization demonstrated a trade-off between three aspects related to recyclability: the amount of in-use copper stock, SD, and PD.

A comparison of different methods and materials for establishing maximal intercuspal position: A clinical study

Statement of problemWhich method or material used to record the intercuspal position yields the best accuracy of location of the maxillary and mandibular casts is unclear. PurposeThe purpose of this clinical study was to determine the most reliable method of recording a patient’s maximal intercuspal position by comparing 2 common methods with 2 popular registration materials. Material and methodsComplete arch impressions were made of both jaws with a polyvinyl siloxane impression material in a metal stock tray followed by 4 interocclusal registrations for each of the 17 participants. Two registration techniques were used. More than 1 record was obtained in the first technique, as the participant had to close through a wax sheet or a polyvinyl siloxane material. In the second technique, a polyvinyl siloxane material was injected from the buccal aspect between occluded tooth surfaces. Casts were made from Type 4 stone and vertical measurements of the casts were carried out by using digital vernier calipers, accurate to 100 μm. Hand articulation of the casts was used as the control. Consistency of measurement was assessed by the intraclass correlation coefficient, and comparisons were made by using repeated-measures regression analysis. ResultsStatistical analysis showed significant discrepancies when the participant closed through both wax and polyvinyl siloxane material (P<.001). No statistically significant differences to the control group were present when polyvinyl siloxane was injected laterally after closure. ConclusionsHand articulation was the most accurate method of reproducing the maximal intercuspal position in a completely dentate individual with horizontal and vertical occlusal stability and was therefore considered the control. Recording the position after the participant had closed by using a polyvinyl siloxane material was the most accurate.